Re: [PATCH 2/3] arm64: dts: rk3399-rock960: add vdd_log

[Kever Yang]

Hi Manivannan,

On 2019/11/13 äå1:17, Manivannan Sadhasivam wrote:
> On Tue, Nov 12, 2019 at 04:10:17PM +0800, Kever Yang wrote:
> > On 2019/11/11 äå1:22, Manivannan Sadhasivam wrote:
> > > Hi Kever,
> > >
> > > On Mon, Nov 11, 2019 at 08:51:57AM +0800, Kever Yang wrote:
> > > > Add vdd_log node according to rock960 schematic V13.
> > > >
> > > > Signed-off-by: Kever Yang <kever.yang@xxxxxxxxxxxxxx>
> > > > ---
> > > >
> > > >    arch/arm64/boot/dts/rockchip/rk3399-rock960.dtsi | 12 ++++++++++++
> > > >    1 file changed, 12 insertions(+)
> > > >
> > > > diff --git a/arch/arm64/boot/dts/rockchip/rk3399-rock960.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-rock960.dtsi
> > > > index c7d48d41e184..73afee257115 100644
> > > > --- a/arch/arm64/boot/dts/rockchip/rk3399-rock960.dtsi
> > > > +++ b/arch/arm64/boot/dts/rockchip/rk3399-rock960.dtsi
> > > > @@ -76,6 +76,18 @@
> > > >    		regulator-always-on;
> > > >    		vin-supply = <&vcc5v0_sys>;
> > > >    	};
> > > > +
> > > > +	vdd_log: vdd-log {
> > > > +		compatible = "pwm-regulator";
> > > > +		pwms = <&pwm2 0 25000 1>;
> > > > +		regulator-name = "vdd_log";
> > > > +		regulator-always-on;
> > > > +		regulator-boot-on;
> > > > +		regulator-min-microvolt = <800000>;
> > > > +		regulator-max-microvolt = <1400000>;
> > > > +		regulator-init-microvolt = <950000>;
> > > The default value seems to be 0.9v as per both Rock960 and Ficus schematics.
> >
> > The default value is 0.9V when pwm-regulator is not enabled, and this
> > 'init-microvolt' suppose to set the
> >
> > init value when pwm-regulator is enabled. I set this to 950mV because Peter
> > report that he experience
> >
> > the system hang during Fedora boot up, and update the vdd_log to 950mV can
> > fix the issue due to
> >
> > engineer measure on another rk3399 board puma-Q7.
> okay. Previously we had post-boot hang issue on Rock960 Model A boards when the
> performance governor was set as default. So the vdd_log node was removed from
> the devicetree. Have you tested that case also?
>
> Here is the commit:
> 13682e524167 ("arm64: dts: rockchip: remove vdd_log from rock960 to fix a stability issues")


For rk3399, the kernel does not touch this regulator, it should be take 
care by bootloader.

So I think we need to update both U-Boot and kernel.


Thanks,

- Kever

> thanks,
> Mani
> > Thanks,
> >
> > - Kever
> >
> > > Other than that,
> > > Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > >
> > > Thanks,
> > > Mani
> > >
> > > > +		vin-supply = <&vcc_sys>;
> > > > +	};
> > > >    };
> > > >    &cpu_l0 {
> > > > --
> > > > 2.17.1